HUBBLE SPACE TELESCOPE - Continuing to collect World Class
Science
DAILY REPORT # 4299
PERIOD COVERED: UT February 13, 2007 (DOY 044)
OBSERVATIONS SCHEDULED
WFPC2 10918
Reducing Systematic Errors on the Hubble Constant: Metallicity
Calibration of the
Reducing the systematic errors on the Hubble constant is
still of
significance and of immediate importance to
modern cosmology. One of the
largest remaining uncertainties in the
Cepheid-based distance scale
{which itself is at the
foundation of the HST Key Project determination
of H_o}
which can now be addressed directly by HST, is the effect of
metallicity on the Cepheid
Period-Luminosity relation. Three chemically
distinct regions in M101 will be used to
directly measure and thereby
calibrate the change in zero point of the
range of metallicities
that run from SMC-like, through Solar, to
metallicities as high as the most
metal-enriched galaxies in the pure
Hubble flow. ACS for the first time offers
the opportunity to make a
precise calibration of this effect
which currently accounts for at least
a third of the total systematic
uncertainty on Ho. The calibration will
be made in the V and I bandpasses so as to be immediately and directly
applicable to the entire HST Cepheid-based
distance scale sample, and
most especially to the highest-metallicity galaxies that were hosts to
the Type Ia
supernovae, which were then used to extend the the
distance
scale calibration out to
cosmologically significant distances.
NIC1/NIC2/NIC3 8793
NICMOS Post-SAA calibration - CR Persistence Part 4
A new procedure proposed to alleviate the CR-persistence
problem of
NICMOS. Dark frames will be obtained
immediately upon exiting the SAA
contour 23, and every time a NICMOS
exposure is scheduled within 50
minutes of coming out of the SAA. The
darks will be obtained in parallel
in all three NICMOS Cameras. The
POST-SAA darks will be non- standard
reference files available to users with a
USEAFTER date/time mark. The
keyword 'USEAFTER=date/time' will also
be added to the header of each
POST-SAA DARK frame. The keyword must be populated
with the time, in
addition to the date, because HST
crosses the SAA ~8 times per day so
each POST-SAA DARK will need to have
the appropriate time specified, for
users to identify the ones they need.
Both the raw and processed images
will be archived as POST-SAA DARKSs. Generally we expect that all NICMOS
science/calibration observations started within 50
minutes of leaving an
SAA will need such maps to remove the CR persistence from
the science
images. Each observation will need its
own CRMAP, as different SAA
passages leave different imprints on the
NICMOS detectors.
NIC3 11064
CYCLE 15 NICMOS SPECTROPHOTOMETRY CALIBRATION PROGRAM
Now that the spectrophotometric capabilities
of the NICMOS grism have
been established, cycle 15
observations are needed to refine the
sensitivity estimates, to check for
sensitivity loss with time, to
improve the accuracy of the linearity
correction, to improve the
secondary flux standards by
re-observation, and to expand the G206 data
set now that the sky subtraction
technique has been shown to produce
useful fluxes for some of the fainter
secondary standards. These faint
secondary IR standards will be a
significant step towards establishing
flux standards for JWST, as well as
for SNAP, Spitzer, and
observe the 3 primary WDs GD71, G191B2b, & GD153 twice each, once at the
beginning and once near the end of the 18
month cycle. To date, we have
only 2 observation of each star, while
the corresponding STIS data set
for these primary standards ranges
from 6 to 23 obs. No observations
exist for GD71 or GD153 with G206, so
that the current G206 sensitivity
is defined solely by G191B2B.
Purposes: Refine sensitivities, measure
sens losses. Orbits: 2 for each of 6
visits = 12 2. Re-observe WD1057 &
WD1657 plus another P041C lamp-on visit to improve the
scatter in the
non-lin measurements per Fig. 8 of NIC
ISR 2006-02. The WD stars require
2 orbits each, while the lamp-on
test is done in one. The very faintest
and most crucial standard WD1657
has 2 good visits already, so to
substantially improve the S/N, two visits of
two orbits are needed.
Include G206 for P041C in the lamp-off baseline part of
that orbit.
Orbits: WD1057-2, WD1657-4, P041C-1 --> 7 3. Re-observe
9 secondary
standards to improve S/N of the faint
ones and to include G206 for all
9. BD+17 {3 obs} is not repeated
in this cycle. Four are bright enough
to do in one orbit: VB8,
2M0036+18, P330E, and P177D. Orbits:2*5+4=14
Grand Total orbits over 18 month cycle 15 is 12+6+14=32 {Roelof will
submit the P041C lamp-on visit in a
separate program.}
NIC3 11080
Exploring the Scaling Laws of Star Formation
As a variety of surveys of the local and distant Universe
are
approaching a full census of galaxy
populations, our attention needs to
turn towards understanding and
quantifying the physical mechanisms that
trigger and regulate the large-scale
star formation rates {SFRs} in
galaxies.
WFPC2 10890
Morphologies of the Most Extreme High-Redshift
Mid-IR-Luminous Galaxies
The formative phase of the most massive galaxies may be
extremely
luminous, characterized by intense star-
and AGN-formation. Till now,
few such galaxies have been
unambiguously identified at high redshift,
restricting us to the study of low-redshift ultraluminous infrared
galaxies as possible analogs. We have
recently discovered a sample of
objects which may indeed represent this
early phase in galaxy formation,
and are undertaking an extensive multiwavelength study of this
population. These objects are bright at
mid-IR wavelengths
{F[24um]>0.8mJy}, but deep
ground based imaging suggests extremely faint
{and in some cases extended}
optical counterparts {R~24-27}. Deep K-band
images show barely resolved galaxies.
Mid-infrared spectroscopy with
Spitzer/IRS reveals that they have redshifts
z ~ 2-2.5, suggesting
bolometric luminosities ~10^{13-14}Lsun! We propose to obtain deep ACS
F814W and NIC2 F160W images of these sources and their
environs in order
to determine kpc-scale
morphologies and surface photometry for these
galaxies. The proposed observations will
help us determine whether these
extreme objects are merging systems,
massive obscured starbursts {with
obscuration on kpc
scales!} or very reddened {locally obscured} AGN
hosted by intrinsically low-luminosity
galaxies.
WFPC2 10913
The Light Echoes around V838 Monocerotis
V838 Monocerotis, which burst
upon the astronomical scene in early 2002,
is a completely unanticipated new
object. It underwent a large-amplitude
and very luminous outburst, during
which its spectrum remained that of
an extremely cool supergiant. A rapidly evolving set of light echoes
around V838 Mon was discovered soon
after the outburst, and quickly
became the most spectacular display of
the phenomenon ever seen. These
light echoes provide the means to
accomplish four unique types of
measurements based on continued HST imaging
during the event: {1} Study
effects of MHD turbulence at high
resolution and in 3 dimensions; {2}
Construct the first unambiguous and fully 3-D map of a circumstellar
dust envelope in the Milky Way; {3}
Study dust physics in a unique
setting where the spectrum and light
curve of the illumination, and the
scattering angle, are unambiguously known;
and {4} Determine the
distance to V838 Mon through direct
geometric techniques. Because of the
extreme rarity of light echoes, this is
almost certainly the only
opportunity to achieve such results during
the lifetime of HST. We
propose two visits during Cycle 15, in
order to continue the mapping of
the circumstellar
dust and to achieve the other goals listed above.
WFPC2 11095
Hubble Heritage Observations of NGC 6050
The Hubble Heritage team will use a single pointing of
WFPC2 to obtain
F450W, F555W, F656N, and F814W images of NGC 6050 as part
of a public
release image.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are
preliminary reports
of potential non-nominal
performance that will be investigated.)
HSTARS:
10689 - GSacq(2,3,3) failed to RGA control
GSacq(2,3,3)
scheduled at 044/17:25:14 failed at 17:29:07 due to Scan
Step Limit exceeded on FGS 2. The OBAD at 17:19:58 showed errors of
V1=2.32, V2=-7.92, V3=24.45, and RSS= 25.80.
10692 - GSACQ(1,2,1) failed,
Search Radius Limit Exceeded on FGS 1
Upon acquisition of signal at 045:08:50:59 vehicle was
in gyro control
with FGS 1 search radius limit flag set. GSACQ(1,2,1)
at 045:08:35:24
failed with search radius limit exceeded. OBAD map after
GSACQ failure
showed RSS error of 6.87 arcseconds.
COMPLETED OPS REQUEST: (None)
COMPLETED OPS NOTES: (None)
SCHEDULED
SUCCESSFUL
FGS GSacq 06 04
FGS REacq
08
08
OBAD with Maneuver
27
27
SIGNIFICANT EVENTS: (None)
-
____________________________________________________________
Lynn F. Bassford
Hubble Space Telescope
CHAMP
Lockheed Martin
NASA GSFC PH#: 301-286-2876
"The Hubble Space Telescope is the
astronomical observatory and key to unlocking the most cosmic mysteries of the
past, present and future." - 7/26/6